Electric switch



C. C. STERLING.

ELECTRICSWITBZLL- APPLICATION mm 3.34.1920;

1,884: ,8 1 0. Patented July 19, 1921.

5] mucm fol UNITED STATES PATENT OFFICE.

CLARENCE c. STIRLING, or IInn'rronn, CONNECTICUT, ASSIGNOB, To THE HART EEGEMALN' MANUFACTURING COMPANY, or HARTFORD, CONNECTICUT, A con- IORATION OF CONNECTICUT..

ELECTRIC SWITCH.

Specification of Letters Patent.

Patented July 19, 1921.

Application filed April 14, 1920. Serial No. 373,791.

To all whom it may concern:

Be it known that CLARENCE C. STIRLI G, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, has invented certain new and ,useful Improvements in Electric Switches, of which the following is a speoification.

This invention relates to electric switches. In a great many cases a fuse or fuses are used in conjunction with an electric switch to render the same automatic. I provide means by which this condition is insured without the use of a fuse. While the device is capable of general use it is of especial utility when the switch with which it is associated is used in connection with. a low powered motor, being of such character as to instantly automatically throw the switch to off to stop the motor, when the latter is overloaded, yet the switch may be independently operated at any time for instance by hand to either start or stop the motor. It will also be clear that when the switch is put into automatic relation and when it is automatically shifted to off relation to stop the motor or perform some equivalent act, it is generally restored to on by hand insome analogous fashion.

In the ,drawingsaccompanying and forming a part of the present specification I have shown in detail one of the several forms of embodiment of the invention which to enable those skilled in the art to practice the same will be set forth fully in the following description. I am not restricted to this showing. I may in fact depart therefrom in several respects within the scope of the invention defined by the claims foll0wingtsaid description. I

eferring to said drawings:

Figure 1 is a top plan view of a switch involving the invention.

Fig. 2 is a side elevation of the same as seen for instance from ,below in Fig. 1 with the casing of theswitch in cross section.

Fig. 3 is a sectional plan view the section being taken vthrou h the spindle of the switch and that of t e magnet, a part of the frame being broken awa Like characters .re er to like parts throughout the several news.

The various parts of the device may be mounted in any convenient mannerfor instancenpon a base as 2 generally made of some insulating material. This might be considered as the main base because as shown there is an auxiliary base as 3 also of insulating material, although it is not always necessary that the same be provided.

The switch mechanism as shown is inclosed in a casing as 4 ordinarily of metal. As a matter of fact the switch shown is of the Well known rotary snap type. The switching mechanism by which the circuit, for instance a motor circuit, is controlled might be of any suitable nature. The switch alsoinvolves a spindle as 5 with which the blades 6 are associated, a spring 6 also being associated with the spindle as is well known. The contacts of the switch mechanism are denoted by 7. By turning the spindle by hand the spring 6' is put under tension so that the spindle when released, will be snapped by the spring between its on and off positions in the well known and customary manner. As illustrated the spindle 5 is provided at its upper end with a knob or finger piece 8 by which it may be operated. I have described but briefly the switch construction per so because it does not necessarily form in itself any part of the invention in that the improvements may be associated with other types of switches. The leads into the switch are denoted by 9.

In series with theswitch is an electri- Cally-operated ,device such as a magnet 10 the lower head of which may be fastened to the element 11 fastened suitably and rigidly to the upper side of the base 2. From the frame member 11 and the post or upright 12 rises and has fastened to it the strip 13 perforated at its inner end to receive the spindle 5, this strip thus presentin a more stable support for the splndle 5. he core 14 of the electro-magnet 10 also extends through the strip 14 thus maintaining said magnet solidly and substantially in position.

its armature to function as 1 will set forth hereinafter. The spindle 5 as shown has rigid therewith the collar or disk 16 having as shown the diametrically-opposite notches 17 in the periphery thereof. The armature for the magnet 10 is designated by 18 and as shown is.in the form of a lever having a fulcrum upon the spindle 5, the lever or armature as a consequence having a motion with respect to the spindle. The fulcrum portion of the armature 18 is forked to straddle the disk or collar 16 and its branches are perforated to receive the spindle. This lever or armature 18 constitutes a suitable support for an actuator such as the spring 19 fastened thereto as by screws 20, between the fulcrum and outer free end of the lever, the active portion of the spring 19 cooperating alternately with the two notches 17 Between the tail portion of the spring 19 and the armature 18 is supported a spring 21, the screws 20 to which 1 have referred presenting a convenient means for holding the sprin 21 in position with its free end against the extended core 14 of the mag,- net 10.

The post or upright 12 to which I have referred is in the nature of a magnet and acts to assist the core of the permanent magnet 10 in attracting the armature or lever 18 when the circuit is overloaded. Normally the sprin 21 by acting against the extended core 0 the magnet 10 operates to hold the actuator or spring 19 inposition to permit the free end of the actuator, spring or'pawl to snap into one of the diametricallyopposite notches 17.

Through the action of the spindle 5 under the influence of the knob 8 the spindle may be turned by hand at any time so that the switch is thus manually governed. It will be assumed that the automatic action of the switch is desired. In this event the spindle 5 is turned by hand thus tensioning the spring 6 of the switch to condition it to snap the switch to ofi at the proper point. Just before the switching mechanism is released to effect the moving of the same ,to the .oif relation, the fore end of the spring or actuator 19 snaps into one of the notches 17 for instance as shown in Fig. 3. It will be assumed that the parts being in this relation the circuit is overloaded. In such case the magnet attractsits armature, the actuator 19 being thus operatedto apply a thrust t0 ;lih8 collar 16 and turn the collar and thereby the spindle 5 to move. the switch to the ca relation and as a result breakthe cir t.

There is shown connected with'the strip 13, a stop member-22 the stop ofwhich is in the form of a screw. 23; in threaded. connection therewith. The screw is of course adjustable and it can be readily manipulated to neeaero adjust the amount of outward movement of the lever or armature 18.

What I claim is:

1. A snap switch provided with a turnable spindle having switching mechanism associated therewith and also having means by which the spindle may be partially operated to cause the switching mechanism to move from on toward off position, and means for automatically completing the off relation when the current reaches a predetermined amount.

2. A snap switch provided with a'spindle having switching mechanism associated therewith and also provided with means by which the spindle may be partially operated at will to effect the movement of the switching mechanism from on toward off posion, an electromagnet electrically connected with the switch, an armature for the magnet, fulcrumed upon the spindle, and a spring pawl carried by the armature to operate against the s indle to complete the off movement 0 the switching mechanism through the turning of the spindle, when the armature is attracted by the magnet.

3. A snap switch provided with a spindle movable about an axis and also provided with means by which the spindle may be operated to move the switch mechanism from on to off or. by which the switching mechanism can be moved at will to effect partial movement of the switch mechanism from on toward off position, and means for automatically completing the OE relation when the energization of said means reaches a predetermined amount.

4. A snap switch provided with a spindle turnable about an axis and also involving switch mechanism associated with the spindle, and means whereby the spindle may be turned manually to efl'ect the partial action of the switch mechanism from on to off position, an electromagnet electrically connected with the switch, and means actuated by the magnet, when the current reaches a predetermined amount for automatically completing the ofi action of the spindle.

5. A snap switch comprising a spindle turnable about an axis and also provided with switching mechanism associated with the spindle, means whereby the spindle may be turned at will to effect partial action of the switch mechanism from the on toward the"olf position, an electromagnet electrically connected with the switch, an armature tobe attracted by the/magnet, when the current reaches a redetermined amount, and meansactuated y thearmatnre, for completing the movement of the spindle and thus complete the movement of the switching 'mechanism to theofi relation.

6. A snapswitch comprising a spindle movable about an axis and also comprising switching mechanism operatively associated armature for completing the movement of 10 with the spindle, means whereby the spindle the switching mechanism to the ofi remay be turned at will to effect artial movelation. v

ment of the switching mechamsm from the In testimony whereof I afiix my signature on to the OE relation, an electromagnet in the presence of two witnesses.

electrically connected with the switch, an CLARENCE C. STIRLING. armature adapted to be attracted by the mag- Witnesses: net, when the current reaches a predeter- ELSIE M. RABENSTEIN,

minedpoint, and a pawl actuated by the HEATH SUTHERLAND. 

